ABSTRACT
Wagenet (Chapter 11) has g i v e n a u s e f u l overv iew o f t h e e f f e c t o f c o n s e r v a t i o n - t i l l a g e (CT) p r a c t i c e s on p e s t i c i d e losses i n water. H i s paper emphasizes t h e need f o r more s t u d i e s comparing l o s s e s between t i l l a g e systems, a more d e t a i l e d l o o k a t c r o p r e s i d u e e f f e c t s . and t h e macropore phenomemon. He a l s o d iscusses t h e q u e s t i o n o f how t o r e p r e s e n t (descr ibe ) s p a c i a l v a r i a b i l i t y , an i s s u e t h a t i s a t t h e h e a r t o f c u r r e n t model ing e f f o r t s .
